Blast deflector



S. LEVMORE BLAST DEFLEGTOR Nov. 8, 1966 Filed March 4, 1964 INVENTOR.

SHEPHERD LEVMORE ATTORNEYS United States Patent 3,283,715 BLAST DEFLECTOR Shepherd Levrnore, Morris Plains, N.J., assignor to the United States of America as represented by the Secretary of the Army Filed Mar. 4, 1964, Ser. No. 349,504 3 Claims. (Cl. 102-22) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The present invention relates to high explosive materials. It is known that, when high explosive charges are placed in close proximity to one-another, if one charge is ignited the adjacent charges are also ignited by sympathetic explosions due to the high intensity shock waves from the first exploding charge. The resulting chain reaction explodes entire magazines and, it the various magazines themselves are located closely adjacent to one-another, one exploding magazine may cause other adjacent magazines to explode. In some situations a series of charges are placed in alignment and it is desired to ignite the charges successively and independently without a chain reaction due to sympathetic explosions.

It has been found that a blast deflector as set forth hereinafter is highly effective in splitting shock waves and preventing sympathetic explosions of closely adjacent charges of high explosives.

In the drawings:

FIG. 1 is a side elevation of two high explosive charges with a blast deflector mounted therebetween positioned for test purposes;

FIG. 2 is a plan view of the apparatus of FIG. 1;

FIG. 3 is a View along line 33 of FIG. 2.

Referring more specifically to the drawings, apparatus for testing effectiveness of the present invention is illustrated wherein blast deflector is mounted on base 12. A charge of high explosive material 14 is mounted on support 16 and a charge of high explosive material 18 is mounted on support 20.

A blast deflector 10 is positioned between charges 14 and 18. The deflector is positioned, designed and shaped such that it will divide or split the shock wave emanating from either charge if it should explode, thus providing a degree of shelter which is adequate to prevent the other charge from exploding by sympathetic explosion.

The charges of high explosives may be squared on their ends, or they may be chamfered as at 22, 24. Assume that charge 14 is exploding. If the end of the charge is chamfered as at 22, the shock wave emanating from the end adjacent to blast deflector 10 does not present the usual blast front. Instead, the shock wave presents a front which travels outwardly with a leading edge of comparatively mild intensity followed by increasing intensity. Thus, an object in the path of the shock wave is subjected to a more gradual build-up of pressure and shock, and the tendency toward destruction of the object is reduced.

Now, assume that shock waves from exploding charge 14 are arriving at charge 18. If the leading edge of the charge is chamfered as at 24 the destructive tendency of the shock wave on charge 18 is reduced because the leading edge tends to plow into the wave much as the pr ow of a ship plows into a wave. Thus, the shock wave is split and is less destructive of the charge itself.

Many successful experimental tests have been performed in accordance with the above general principles. Many different shapes and materials have been tested and found satisfactory for the blast deflector. Use of a blast deflector has proven adequate to prevent sympathetic explosions even where the ends of the charges are not chamfered. However, by chamfering the ends a greater degree of safety is obtained, or the blast deflector can be made smaller or with a lower degree of blast deflection. Thus, with a blast deflector, or with a blast deflector and chamfered ends of charges, sympathetic explosions can be prevented even where the high explosive charges are in close proximity to one-another, say ten inches apart.

I claim:

1. Apparatus for preventing sympathetic explosion of a charge of explosive material in response to explosion of another nearby charge comprising a first charge and a second charge, shock wave deflecting means between said charges, shock minimizing means comprising a tapered end on one of said charges to cause a blast wavefront emanating therefrom to be minimized in destructive tendency as the charge explodes, and shock-wave splitting means on the other of said charges to split an incoming blast wave-front.

2. Apparatus as in claim 1 wherein said first charge, said second charge and said shock-wave deflecting means are in substantial alignment.

3. Apparatus as in claim 2 wherein said sh0ck-wave minimizing means and said shock-wave splitting means are turned substantially toward said shock-wave deflecting means.

References Cited by the Examiner UNITED STATES PATENTS 701,922 6/1902 Nelson 89-36 2,818,808 1/1958 Dill 102-20 3,054,471 9/1962 Knudsen 181O.5

SAMUEL FEINBERG, Primary Examiner.

BENJAMIN A. BORCHELT, Examiner.

R. V. LOTTMANN, V. R. PENDEGRASS,

Assistant Examiners. 

1. APPARATUS FOR PREVENTING SYMPATHETIC EXPLOSION OF A CHARGE OF EXPLOSIVE MATERIAL IN RESPONSE TO EXPLOSION OF ANOTHER NEARBY CHARGE COMPRISING A FIRST CHARGE AND A SECOND CHARGE, SHOCK WAVE DEFLECTING MEANS BETWEEN SAID CHARGES, SHOCK MINIMIZING MEANS COMPRISING A TAPERED END ON ONE OF SAID CHARGES TO CAUSE A BLAST WAVE-FRONT EMANATING THEREFROM TO BE MINIMIZED IN DESTRUCTIVE TENDENCY AS THE CHARGE EXPLODES, AND SHOCK-WAVE SPLITTING MEANS ON THE OTHER OF SAID CHARGES TO SPLIT AN INCOMING BLAST WAVE-FRONT. 